ABSTRACT As the number of women veterans continues to increase as a result of changes in the composition of the active duty military, there is an increasing need to understand the healthcare needs of this growing segment of the patients we serve. Projections based on the number of women currently serving in the military suggest that by 2020 women will represent approximately 10% of the total veteran population. Sleep disorders are common in women, with a mean prevalence among U.S. women of 23%. However, a 2006 systematic review of VA women's health research did not identify any prior studies of sleep disorders in women veterans. This pilot study will be the first exploration of insomnia among women veterans receiving care within VA. This study will have three key aims: 1) Estimate the prevalence of insomnia complaints among women veterans;2) Describe the medical, psychiatric and lifestyle factors associated with sleep among women veterans with insomnia;and 3) Identify treatment preferences among women veterans with insomnia. All are intended to inform development of a larger future study of insomnia among women veterans who receive VA healthcare. The aims will be achieved by conducting a two-phase study. In Phase I, a mail survey, including a validated insomnia questionnaire will be sent to 1,700 women veterans who receive care within VAGLAHS. This will be used to estimate the rates of insomnia (Aim 1) and to identify potential participants for Phase II. In Phase II, a descriptive study of subjective (questionnaire) and objective (wrist actigraphy) sleep, plus a battery of other clinical measures will be carried out with 85 women veterans who return the survey indicating insomnia problems and provide informed consent to participate. Phase II participants will wear a wrist actigraph for one week (to objectively monitor sleep/wake patterns), and will complete a clinical assessment battery addressing factors that are associated with insomnia and potential consequences of insomnia. Participants will also be queried about their interest in insomnia treatment and their specific treatment preferences (pharmacological, behavioral, group, individual, etc.). Medical records will be reviewed for information on VA healthcare utilization, ICD-9 codes for sleep disorders, and medications. Analysis of data will include descriptive and summary statistics as well as regression models predicting insomnia severity and objective sleep quality (based on actigraphy). The proposed study represents a much-needed first step in understanding sleep problems among women veterans. We anticipate that the results will suggest a larger descriptive study is needed to prospectively follow women veterans and determine the impact of insomnia on mental and physical health outcomes. This pilot study will begin a line of research targeting the development and implementation of insomnia interventions for women veterans, taking into account the specific characteristics of women veterans with insomnia and their specific treatment preferences.